So what exactly are the hormones that are considered “bioidentical”? Well, there really aren’t that many that we need to discuss.
The important hormones can be broken into two groups, the steroid hormones and the non-steroid hormones. When people hear the word “steroid” they often think of athletes using drugs to get pumped up. This type of “steroid” is more accurately called an “anabolic steroid”. Anabolic means “building up”, so these are hormones that build up muscle, usually testosterone or a synthetic version of testosterone. We use testosterone in bioidentical hormone replacement therapy (BHRT), but only as a way to balance hormones and treat symptoms, not to allow us to hit home runs.
Basically, steroid hormones are any hormone that is based on the chemical structure of the cholesterol molecule. This brings up an important side note - cholesterol is absolutely necessary for the healthy functioning of the body. And although the body has the ability to manufacture cholesterol, we still need to get some from our diet. A zero cholesterol diet is a sure fire way to achieve hormonal imbalance. We can talk about cholesterol at future posts, but I just wanted to put that in there.
Before I talk about specific hormones, I want to review what it means for a hormone to be bioidentical. If you haven’t done so, please see my earlier post entitled Key Principles of Bioidentical Hormone Replacement (BHRT). The basic explanation is that bioidentical hormones are chemically and structurally exactly the same as human hormones. And when I say exactly, I mean exactly. There cannot be even one little slight difference. If there is an extra hydrogen atom on the molecule then it is not bioidentical. In a future post, I will use progesterone as an example as to why it is so important that the hormones are identical.
The picture to the left shows the steroidogenic cascade. This is basically a chart of how the body takes cholesterol (upper-left hand part of the chart) and changes it into the various hormones it needs. Although there are lots of hormones on this list, we only supplement with a few. The most important are the estrogens, progesterone, testosterone, DHEA, and cortisol.
1. Estrogens – there are only 3 bioidentical estrogens, estrone (E1), estradiol (e2) and estriol (E3). Estradiol is the most commonly used and the strongest of the three estrogens. For the sake of keeping this post a reasonable length, I will discuss these indivudial hormones more extensively in future posts.
2. Progestin – there is only one progestin that the body uses and that is progesterone. Progesterone is an extremely important hormone and is often overlooked.
3. Testosterone – this is thought of as a hormone for men although women need it too, just not as much of it.
4. DHEA – this hormone is a precursor to testosterone and although current evidence suggests that the body doesn’t use DHEA directly, sometimes it is given to women who have low energy, muscle wasting, and low libido. Personally, I have had better luck giving testosterone instead of DHEA to women who have those symptoms, but other practitioners do use it.
5. Cortisol – aka “the stress hormone”. Cortisol is released from the adrenal glands in response to stress. Abnormal cortisol secretion and its resulting health problems is commonly known as “adrenal fatigue”.
Of the non-steroid hormones, the ones worth mentioning are the thyroid hormones, namely levothyroxine (T4) and liothyronine (T3). These are peptide hormones, meaning that their chemical structure is basically a long chain of amino acids as compared to the steroid hormones which are modified cholesterol molecules. As a side note, steroid hormones have very good penetration through the skin. That is why estrogens, progesterone, etc. can be given as creams. Peptide hormone have very poor skin penetration which is why we give thyroid supplementation as an oral medication.
T3 is the active thyroid molecule, meaning that it is the form that exerts its effects on the body’s cells. However, the body produces T4 in the thyroid gland and converts it to T3 in the blood vessels. The most commonly prescribed thyroid supplementation is oral T4 or levothyroxine (Synthroid, Levoxyl, etc.). For most people, this is adequate to treat their symptoms of low thyroid. A small percentage need T3 supplementation to effectively treat their symptoms. This can be given orally by a prescription off-the shelf medication (Cytomel), in combination with T4 (Armour Thyroid, Thyrolar), or can be made by a compounding pharmacy.
There is just a lot to talk about and I don’t want to make anyone’s eyes glaze over. I you have any specific questions, please post them as a comment to this blog posting and I will do my best to answer them.
Thank you and live well!